1

Creating Value from

Non-carbon 2D Materials

- beyond Graphene

A State of the Art Review

2

Table of contents

Executive Summary 3

Glossary of Non-Carbon 2D Materials 5

Introduction 6

Family of Non-Carbon 2D Materials 7

Production of Non-Carbon 2D Materials 9

The Innovation Landscape for Non-Carbon 2D Materials 11

Strategic Insights for the UK 16

Conclusions 20

Priorities and Recommendations 20

Acknowledgements 21

References 22

Appendix 1 Examples of R&D and Innovations 23

Appendix 2 Patent Analysis 24

3

Executive Summary

The ability to isolate or grow two-dimensional (2D) materials has been a source of scientific

fascination ever since it was shown to be possible with the isolation of graphene from

graphite in 2004 at the University of Manchester in 2004. The increasing range of 2D

materials extends far beyond graphene and its carbon analogues. It is believed that over 500

2D materials have been developed globally so far and these materials exhibit an exciting

range of novel properties that open the door to a multitude of new potential applications.

Research in non-carbon 2D materials is accelerating at a rapid pace with significant

contributions from UK research groups and materials producing SMEs. Clear progress has

been made with the commercial availability of hexagonal Boron Nitride, hBN, and the

growing industry interest in transition-metal dichalcogenides (TMDCs), in particular

semiconductor TMDCs such as molybdenum disulphide (MoS2) which have direct gap and

are attractive for optics and optoelectronic devices. There is also a particular excitement

about the ability to custom stack thin layers of non-carbon 2D materials and in combination

with graphene to create hetero-structured devices. These devices have a variety of different

electronic and optical properties, which can be finely tuned by careful design of the stack.

Ongoing research is showing great promise for new materials with specially designed

electrical, magnetic, piezoelectric and optical functionalities.

Research in non-carbon 2D materials has benefited from the investments in developing

graphene with complimentary developments that address graphene’s major weakness in its

lack of a band gap; a property that makes silicon and other semiconductors so useful for

digital electronics. 2D semiconducting materials are likely to become an attractive choice for

constructing digital circuits on flexible and transparent substrates for applications such as

paper-like transparent displays, wearable electronics and photonic devices. A range of

industries recognise the benefits they can derive from these new materials and have

expressed the need to have greater understanding of the industrial challenges they will face.

This has led to the KTN undertaking a short project to bring together leading companies and

academics working on 2D materials and devices from across UK and to meet with potential

industry users and the wider supply chain to explore the challenges faced in bringing these

2D materials to market. This output from the project includes this state of the art report,

which reviews the current innovation landscape and captures the views of senior academics

and industrialists in terms of where the UK should be heading to create commercial value

from developments in non-carbon 2D materials.

This KTN study has identified a body of work being undertaken globally to develop non-

carbon 2D materials, mainly led by university research groups. Companies such as

Samsung and IBM are active in this area and so are UK SMEs such as Thomas Swan. The

discussions KTN have had with UK companies suggest that existing businesses with an

interest in developing commercial applications for graphene are the ones most likely to look

at exploiting other 2D materials. The following were noted as the priorities for the UK in our

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bid to create commercial value from current research and industry activities:

• More work needed to scale up the manufacturing and use of 2D materials;

• Funding is needed to improve manufacturing techniques for 2D materials,

devices and products;

• UK industry needs to be more open about their trends and drivers with regards to

2D materials and to work closely with academic researchers to develop

technology roadmaps for mass production and application of 2D materials.

Following considerable discussions with industry experts and academics, the following

recommendations are made to both government and industry to drive forward the

commercialisation of non-carbon 2D materials in the UK.

1. Create an Industry Challenge around hBN and MOS2 to accelerate the development

of supply chain and end user partnerships.

2. Provide 5-10 years long term funding for centres of excellence to carry out more work

needed in scale-up of non-carbon 2D material production, device fabrication and end-

user applications.

3. Consider the overall UK landscape and alignment with the EU Graphene Flagship

project.

4. Invest in scaled-up demonstrators to show and exploit the game changing properties

of non-carbon 2D materials, solely or in combination with graphene.

5

Glossary of Non-Carbon 2D Materials

CuO – Copper oxide

hBN - hexagonal Boron nitride

HfS2, - Hafnium disulfide

LaNb2O7 - Lanthanum niobate

MnO2 – Manganese dioxide

MoO3 - Molybdenum trioxide

MoS2 - Molybdenum disulfide

MoSe2 - Molybdenum diselenide

MoTe2 - molybdenum ditelluride

NbS2 - Niobium disulfide

NbSe2 - Niobium diselenide

Ni(OH)2 – Nickel hydroxide

ReS2 – Rhenium disulfide

ReSe2 – Rhenium diselenide

RuO2 – Ruthenium dioxide

SnS2 - Tin disulfide

SnSe2 – Tin diselenide

TaS2 – Tantalum disulfide

TiO2 - Titanium dioxide

TiS2 - Titanium disulfide

TiSe2 - Titanium diselenide

TMDC - Transition-metal dichalcogenides

VS2 - Vanadium disulfide

VSe2 - Vanadium diselenide

WO3 – Tungsten trioxide

WS2 - Tungsten disulfide

WSe2 - Tungsten diselenide

WTe2 - Tungsten ditelluride

ZrS2 - Zirconium disulfide

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1. Introduction

Two-dimensional (2D) materials are new and expanding family of materials with exceptional

properties. Graphene is currently the most famous of these 2D materials, which although

one million times thinner than paper is the strongest material known to science. It is made up

of carbon atoms arranged in a hexagonal lattice and has many superlative properties to its

credit. The unique combination of superior electrical, optical and mechanical properties

make graphene an incredible material for diverse applications across many sectors. The UK

has been a global leader in research on graphene since its isolation from graphite crystal at

the University of Manchester in 2004.

The ability to isolate or grow 2D materials has been a source of scientific fascination ever

since it was shown to be possible, with the isolation of graphene leading to the discovery of

a whole family of 2D materials, including large number of atomic layers derived from non-

carbon 2D materials such as hexagonal boron nitride (hBN) and molybdenum disulphide

(MoS2). These can be combined with graphene to create exciting new devices and products.

This field is accelerating at a rapid pace and significant contributions have been made by UK

researchers, which includes the ability to build custom-made structures (hetero-structures)

by stacking combinations of 2D materials on top of each other and constructing libraries of

crystals to provide specific electrical, thermal, physical or mechanical properties and

functionalities. A number of these non-carbon 2D materials address graphene’s major

weakness in its lack of a band gap, which is what makes silicon and other semiconductors

so useful for digital electronics. 2D semiconducting materials are likely to become an

attractive choice for constructing digital circuits on flexible and transparent substrates for

applications such as paper-like transparent displays, wearable electronics and photonic

devices. In addition, the mechanical properties of MoS2 also appear to be very attractive. It is

thought that there may be around 500 2D materials already developed, globally, including

graphene.

Research in non-carbon 2D materials has benefited from the investments in developing

graphene with activities in areas of material structure-property correlations, synthesis and

nanofabrication, device integration and device characterisation studies. A range of

industries recognise the benefits they could have from these new materials and have

expressed the need to have greater understanding of the industrial challenges they will face.

This has led to the KTN undertaking a short project to bring together leading companies and

academics working on 2D materials and devices from across UK and to meet with potential

industry users and the wider supply chain to explore the challenges faced in bringing these

2D materials to market. The output from the project includes this state of the art report,

which reviews the current innovation landscape and captures the views of senior academics

and industrial community in terms of where the UK should be heading to create commercial

value from developments in non-carbon 2D materials.

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Definition of 2D Materials

An ISO terminology standard ISO/TS 80004-13:2017: ‘Graphene and related two-

dimensional (2D) materials’ is in preparation to provide a common definition of 2D materials.

The current draft defines 2D materials as “one or several layers with the atoms in each layer

strongly bonded to neighbouring atoms in the same layer, which has one dimension, its

thickness, in the nanoscale or smaller, and the other two dimensions generally at larger

scales”.

2. Family of Non-carbon 2D Materials

Some academics claim that non-carbon 2D materials can outperform graphene and pave the

way to an exciting range of novel applications. They base their views on the fact that graphene

has failed to deliver the required electrical and optical performance for applications such as

photodetectors or digital electronics due to the lack of band gap. The band gap

property/function is often found in other 2D materials, which in turn can be tuned through

material processing, for instance, by changing the number of layers. A summary of the most

known and researched non-carbon 2D material families is shown in Table 1. One example is

the 2D hexagon Boron Nitride, hBN, also called “white graphene”. hBN exhibits a natural band

gap whilst providing good thermal conductivity. Another family of non-carbon 2D materials are

the transition-metal dichalcogenides (TMDC) nanosheets. This family of layered materials,

which include molybdenum disulphide (MoS2), stabilise in a similar hexagonal structure and

can exhibit a wide range of electronic properties ranging from semiconductor, metallic and

even superconducting properties. This can be achieved by manipulating their composition,

geometry, thickness and electronic density (Novoselov, 2016). Another family are the 2D

oxides such as layered CuO, MoO3 and WO3. These are known to exhibit lower dielectric

constant but larger band gaps than their 3D equivalents. Other 3D oxides have been reported

to have been successfully exfoliated down to monolayers to create 2D structures, e.g. TiO2,

MnO2, RuO2 and perovskite LaNb2O7, etc. More recently, a new group of semiconductor 2D

materials have been synthesised. These are made up of single elements such as silicene,

phosphorene and germanene nanosheets. This class of material tends to react with oxygen

and thus highly unstable in ambient conditions.

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Table 1 Non-carbon 2D materials [(Novoselov, 2016), (Geim, 2013)]

Hexagonal boron nitride, hBN

● Large band gap in the UV range of the spectrum.

● Resistant to mechanical and chemical interactions.

● High dielectric strength. For instance, it can sustain electric fields up to 0.8V/nm.

● Application: substrate or encapsulation for 2D devices. For instance, combined with

graphene, hBN greatly improves the mobility of graphene devices. Due to high

dielectric strength, these have been characterised as gate dielectrics and tunnel

barriers.

Transition-metal dichalcogenides, TMDCs

● Compositions include WSe2, MoSe2, MoS2, MoTe2, WTe2, NbSe2, NbS2, TaS2.

● Large optical absorption and band gap in the visible range of the spectrum.

● Wide range of electronic properties can be obtained, from insulating, semiconducting

to metallic or semi-metallic. Properties can be tailored by changing composition,

thickness, geometry and electronic density

● Thin, transparent and flexible materials.

● Applications include photovoltaic devices and photodetectors. For instance, a WS2

300 nm film can absorb 95% of light. Moreover, semiconductor TMDCs with a direct

gap like MoS2 are attractive for optics and optoelectronics devices.

2D oxides

● Compositions include TiO2, MnO2, RuO2, perovskite LaNb2O7, hydroxide Ni(OH)2

● Large band gap.

● Low dielectric constant.

● Biocompatible and non-toxic.

● High surface to volume ratio and surface reaction.

● High adsorption and catalytic efficiencies.

● Applications include immobilisation of biomolecules, like enzymes and antibodies.

Single element

● Compositions include silicene, germanene and phosphorene.

● Exhibit natural band gap.

● Highly unstable (react with oxygen and water).

● Grown on metallic substrates.

● Mostly theoretical work.

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3. Production of Non-carbon 2D Materials

Synthesis of 2D materials can be cost-effective and easy. This is due to the fact that the 3D

compound counterparts tend to be bonded through weak bonds, i.e. Van der Waals bonds.

Mechanical exfoliation is so far the most common method and uses the “Scotch tape”

method as for graphene. It is less destructive compared with other methods and able to

create large single layer flakes on different substrates. Examples of non-carbon 2D materials

produced by this method include TMDCs and hBN. Although cost effective, it is rather

limiting for large amounts of material. Alternative methods are available to synthesise single

to few layer 2D materials and these depend on the desired structure of the materials and

application. Examples are:

● Chemical exfoliation – the crystal is dispersed in a solvent, with compatible surface

tension. TMDCs and hBN can be synthesised by this method.

● Atom/molecule intercalation – this method consists of inserting a molecule or atom

into layered structured compounds. e.g. TMDCs or hBN

● Surface growth - this method entails the deposition of materials on substrates. Single

element nanosheets, such as silicene are often synthesised by this method using

metallic substrates.

● Solution phase growth - this method allows a straightforward production of grammes

of 2D materials, with precise thickness. Examples of colloidal synthesised materials

include TMDCs such as TiS2, VS2, ZrS2, HfS2, NbS2, TaS2, TiSe2, VSe2, and NbSe2.

● Vapour deposition - most commonly used is chemical vapour deposition (CVD) which

is a non-catalytic process for TMDCs.

● Large area CVD - very often to synthesise large areas of graphene and is similarly

suitable for hBN.

The following summarises some the key developments taking place around the world to

provide scalable volumes of non-carbon 2D materials. Appendix 1 provides further details.

Production of 2D Boron Nitride in the UK

Thomas Swan Ltd, UK

(Thomas Swan, 2016) Thomas Swan has launched a new range of 2D hBN materials which were synthesised by direct liquid exfoliation and exhibit high dielectric strength and thermal conductivity. Dielectric 2D hBN is available as few to many layers platelets powder and water/surfactant dispersion. These products are targeting applications as barrier additives, thermal interface materials and thermal conductivity enhancers for plastics, electronics and dielectric oils.

2D nanomaterials solutions

University College London, United Kingdom

(Cullen, 2017) Researchers have developed a scalable and stable production process of 2D

materials solutions through their dissolution in polar solvents. According to this work, this

process monolayers to be achieved by maintaining the 2D material morphology.

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Large-scale growth of high-quality of MoTe2 and WTe2

Nanyang Technological University, Singapore

(Zhou, 2017) Researchers have developed a CVD method to able to synthesise high quality and large area (up to 300 µm lateral size) of atom thin MoTe2 and WTe2. Electric-transport characterization of the grown 2D materials indicate that semi metal and insulator properties in WTe2 and superconductivity in MoTe2. This was the first time that large-scale monolayer ditellurides have been synthesized.

Stacking of 2D Layers - Heterostructures

The stacking of different 2D crystals can result in a charge redistribution between

neighbouring crystals and/or can cause structural changes. Both phenomena can lead to

interesting properties. One may combine components made of different 2D materials or

stack different 2D materials to make a component with finely tuned properties. The so called,

‘Van der Waal heterostructures’ properties can then be tailored by the stacking order,

spacing and orientation of the materials. Examples found include graphene, MoS2 and WSe2

stacked together to make junctions for solar cells (Lee, 2014) and photodetectors (Zhang,

2014). There are examples of work carried out by UK researchers, including creating a

sandwich of MoS2 monolayers between graphene electrodes to make a light-emitting diode

(LED) (Withers, 2015).

Van der Waals heterostructures for solar cells and photodetectors

Manchester University, UK

(Britnell, 2013) UK researchers have shown that a single-layer of WS2 significantly enhances light-matter interactions, thus improving photon absorption and electron-hole creation. In this work, WS2 was sandwiched between transparent graphene electrodes, through which photons were collected. The WS2/Graphene heterostructure resulted in a photoresponsivity above 0.1 amperes per watt.

2D materials for biosensor devices

University of California, US

(Sarkar, 2014) A FET biosensor has been developed and demonstrated based on MoS2 layered material which, according to the researchers, eases patternability and device fabrication. This research demonstrated an extremely high pH sensitivity (713 for a pH change by 1 unit), which surpassed graphene by more than 74-fold. Researchers have put this forward as a promising technology that will allow for the fabrication of flexible, transparent and low-cost biosensing.

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4. The Innovation Landscape for Non-Carbon 2D Materials

As part this KTN study, innovations in non-carbon 2D materials were tracked through bibliometric and patent analysis and by benchmarking available commercial products and other relevant initiatives. The findings are presented below. Scientific Publications

The last 6 years has seen an exponential growth in scientific publications on 2D materials.

The increasing trend started in 2010, 6 years after the isolation of graphene and on the year

of the Nobel prize for graphene (Figure 1). It is also the year, that Splendiani et al, from

University of California, presented their work on the synthesis and photoluminescence

properties of “low-dimensional” MoS2. The most cited papers are shown in Table 2 below.

Figure 1 Number of scientific publications since 2000. Source: Web of Knowledge index. Keyword search: “2D

materials”

Table 2 Top 5 most cited papers in the field of 2D materials. Source: Thomson Reuters' Web of

Science.

Rank Title and reference

1 Experimental observation of the quantum Hall effect and Berry’s phase in graphene By: Zhang, YB; Tan, YW; Stormer, HL; et al. NATURE Volume: 438 Issue: 7065 Pages: 201-204 Published: 10 Nov 2015

2 Single-layer MoS2 transistors By: Radisavljevic, B; Radenovic, A; Brivio, J; Giacometti, V; Kis, A NATURE NANOTECHNOLOGY Volume: 6 Issue: 3 Pages: 147-150 Published: Mar 2011

3 Electronics and optoelectronics of two-dimensional transition metal dichalcogenides By: Wang, QH; Kalantar-Zadeh, K; Coleman, JN; et al. NATURE NANOTECHNOLOGY Volume: 7 Issue:11 Pages: 699-712 Published: Nov 2012

4 Emerging photoluminescence in monolayer MoS2 By: Splendiani, A; Sun, L; Zhang, Y; Li, T; Kim, J; Chim, CY; et al. NANO LETTERS Volume: 10 Issue: 4 Pages:1271-1275 Published: Apr 2010

5 Black phosphorus field-effect transistors By: Li, L; Yu, Y; Ye, GJ; Ge, Q; Ou, Z; Wu, H; Feng, D; et al. NATURE NANOTECHNOLOGY Volume: 9 Issue: 5 Pages:372-377 Published: May 2014

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Synthesis and application of non-carbon 2D materials research are among the most cited.

Table 2 shows that 3 out of 5 most cited papers focus on the synthesis and application of

TMDC materials, e.g. MoS2. These were papers written by research groups from University

of California, MIT, Fudan University (China) and EPFL.

Our analysis found that around 71.3% of scientific papers were published by institutions in

the USA and China, as shown in Table 3, with a large gap between them and Germany (3rd

in the ranking).

Table 3 Top 10 countries contributing to 2D

materials innovation. Source: Thomson

Reuters' Web of Science.

Rank Country %

1 USA 41.3%

2 China 30.0%

3 Germany 7.4%

4 South Korea 6.9%

5 Singapore 6.5%

6 Japan 5.4%

7 England (UK) 5.2%

8 France 4.3%

9 Italy 3.3%

10 Spain 3.1%

Table 4 Top 20 organisations contributing to 2D materials

innovation based on the bibliometric analysis. Source:

Thomson Reuters' Web of Science.

Rank Organisation %

1 Chinese Academy of Sciences 5.9%

2 MIT 3.0%

3 National University of Singapore 3.0%

4 Nanyang Technology University 2.9%

5 Rice University 2.9%

6 Peking University 2.7%

7 University of California Berkeley 2.6%

8 Oak Ridge National Laboratory 2.3%

9 Stanford University 1.9%

10 University of Science and Technology China

1.8%

11 Penn State University 1.8%

12 Ecole Polytechnique Fédérale de Lausanne

1.7%

13 University of Texas Austin 1.7%

14 Columbia University 1.5%

15 Tsinghua University 1.5%

16 Cornell University 1.4%

17 University of Manchester 1.4%

18 National Institute of Materials Science

1.3%

19 Sungkyunkwan University 1.3%

20 Northwestern University 1.2%

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UK is ranked as the 7th country contributor to scientific publications on 2D materials.

University of Manchester leads this ranking in the UK, responsible for 1.4% of the UK’s

5.2% of scientific papers on 2D materials produced worldwide.

Patents

South Korea leads the patent ranking with the top ranking company being Samsung

Electronics and SJE Steel Corporation fifth ranking. IBM, in the USA, ranks second.

Table 4. Top 5 organisations contributing to the 2D materials patent landscape. Source:

Google scholar, Date: 24/03/17.

Top 5 organisations Country %

1. Samsung Electronics Co. Ltd 2. International Business Machines Corporation (IBM) 3. Hitachi Chemical Co. 4. Taiwan Semiconductor Manufacturing Company Ltd 5. SJE Steel Corporation

South Korean USA Japan Taiwan South Korean

4.6% 2.8% 2% 1.8% 1.6%

Although large corporations such as Samsung Electronics, IBM, Hitachi, are leading the

number of patents on non-carbon 2D materials in the world, the trend is different in the UK,

with Universities (e.g. University of Manchester) and SMEs (e.g. Thomas Swan) patenting

the most (Table 5).

Table 5. Examples of UK patents. Google patent database was used to search for patented technologies.

Advanced search of keyword “2D materials” was conducted and 486 hits were obtained.

Two-dimensional materials, Thomas Swan & Co. Ltd (WO, 2014). This patent describes a method of synthesise a 2D material, like graphene or boron nitride.

Functionalised material, Imperial Innovations Ltd (GB, 2014, Pending).

Photovoltaic cells, University of Manchester (US, 2012, Pending). Patent describes a

photovoltaic cell based on graphene and TMDC heterostructure.

Method for producing dispersions of nanosheets, UCL Business Plc (WO, 2014).

Patent describes a method to produce 2D material solutions.

Methods for the production of 2-d materials, 2-Dtech Limited and Innovation Ulster

Limited (WO, 2014). Patent describes a production process of graphene and other 2D

materials.

Exfoliation, The University Of Manchester (WO, 2014). Patent describes a method to

synthesise 2D materials by exfoliating layered materials in aqueous media.

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Volume Production of Non-carbon 2D Materials

SMEs in the UK and the USA are producing non-carbon 2D materials for the research

market. Table 6 provides examples of companies and commercially available materials,

which that hBN and MoS2 are the most commercially developed of the family of non-carbon

2D materials.

Table 6: Examples of companies and commercially available non-carbon 2D materials products.

Companies Products Country

Thomas Swan Ltd hBN powder and dispersion UK

Graphene Supermarket https://graphene-supermarket.com/

hBN, MoS2, WS2 US

Manchester Nanomaterials http://mos2crystals.com/

hBN, MoS2, MoSe2, WS2, WSe2, WTe2 UK

2DSemiconductors http://www.2dsemiconductors.com/

CVD monolayers of MoS2, WS2, MoSe2, WSe2, WS2, SnS2, SnSe2, ReS2 and ReSe2 on sapphire, quartz, SiO2/Si, PET substrates.

US

Ossila https://www.ossila.com/

MoS2 and WS2 monolayers and multilayers. UK

Centres of Excellence

Earlier we saw, in Table 4, the worldwide institutions that most contributed to scientific

publications in 2D materials. In the UK, other centres of excellence are working closely with

industry to support the development of 2D material manufacturing, scaling up and

application. The following centres are active in pursuing activities that are aimed at helping

industry to exploit the exciting properties of 2D materials:

National Graphene Institute Synthesis, manufacturing, application

Cambridge Graphene Centre Synthesis, manufacturing, application

High Value Manufacturing Catapult (CPI) Manufacturing, application

National Physical Laboratory Characterization, standards

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Availability of Roadmaps

Our study has found that only a few roadmaps and market reports mention non-carbon 2D

materials. These reports highlight R&D trends for both graphene and other 2D materials as

well as industrial opportunities (see Table 7).

Table 7: Technology roadmaps and market reports for non-carbon 2D materials.

Technology roadmaps

Science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems (RSC, 2014)

Bulk Nanostructured Materials Based on Two-Dimensional Building Blocks: A Roadmap (ACSNano, 2015)

Opportunities for 2D Materials in Semiconductor Industry. Frost&Sullivan, 2016

2D Nanomaterials in Industrial Applications. Frost&Sullivan, 2017

Graphene, 2D Materials and Carbon Nanotubes: Markets, Technologies and Opportunities 2016-2026

(IDTechEx Research report, 2017)

Knowledge Sharing Initiatives

A number of graphene-community activities have expanded their scope to non-carbon 2D

materials. These involve joint initiatives (e.g. consortium, conferences), which transfer

knowledge and experience from graphene to non-carbon 2D materials (Table 8).

Table 8 2D materials initiatives.

Initiative Type of activity

innoLAE2017, 31 Jan- 1 Feb 2017, Cambridge, UK

Conference

From Datacom to IoT, Enabled by Graphene, 2 March 2017, Barcelona, Spain

Conference

Graphene 2017, 27-28 March 2017, Barcelona, Spain Conference

IDTEchex: Graphene and 2D materials, 10-11th May 2017, Germany

Conference

UK semiconductors, 12-13 July, Warwick, UK Conference

Graphene & 2-D Materials Conference: From Research to Applications, NPL, UK

Conference

Graphene and 2D Materials USA 2017 Conference

EU Graphene Flagship Consortium of over 150 academic and industrial research groups from 23 countries.

Recent Progress in Graphene & 2D Materials Research, September 2017 in Singapore

Conference and Graphene Technology Transfer Fair

EUREKA Cluster “Graphene and 2D Materials” Eureka cluster proposal focused on industrial collaboration. TRL>5. Currently opened for expressions of interest.

Analysis of publicly funded projects found very few businesses leading non-carbon 2D

materials. Table 9 shows examples of the types of projects receiving grant funding.

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Table 9: Ongoing UK and European R&D projects. Sources: Gateway to Research

(http://gtr.rcuk.ac.uk/), Innovate UK Funded Projecst Database

(https://www.gov.uk/government/publications/innovate-uk-funded-projects) and Cordis database

(http://cordis.europa.eu/)

Innovate UK

Two-Dimensional graphene-related Transition metal dichalcogenides for ultracapacitor Energy-storage Devices (2D TREND), DZP Technologies Limited, NPL, Set 16 – Aug’ 17

EPSRC

Engineering van der Waals heterostructures: from atomic level layer-by-layer assembly to printable innovative devices, Lead organization: University of Manchester, Mar 16- Mar 21

Investigation of the Radiation Damage Mechanisms in Two-Dimensional Materials under Gamma and Ion Irradiation, Lead organization: Manchester University, Sep 16 - Mar 20

A systematic investigation of plasmonics in the non-classical regime with two-dimensional materials, Lead organization: Queen's University of Belfast, Oct 16 - Mar 18

Two-dimensional III-VI semiconductors and graphene-hybrid heterostructures, Lead organization: Nottingham University, Apr 15 - Jun 18

Horizon2020/ERC funded projects

Atomic layer deposition of two-dimensional transition metal dichalcogenide nanolayers, Coordinator Organisation: Technische Universiteit Eindhoven, Aug 15 - Jul 2020

Layered functional materials - beyond 'graphene', Coordinator Organisation: Univerzita Karlova, Aug 16 - Jul 21

Toxicity of Non-carbon 2D Materials

Research has been carried out to assess the toxicological impact of 2D materials.

For example, MoS2 and MoSe2 have been found to present low toxicity to lung cancer cells

compared to WSe2. However, the later still shows lower toxicity than the already proven

biocompatible graphene and graphene oxide. It has been increasingly accepted by the

scientific community that cytotoxicology is strongly affected not only by the chemical

composition and defect density, but also by parameters associated with the production

process. For instance, it has been found that exfoliated MoS2 nanosheet in vitro cytotoxicity

depends on the intercalating agent used for the exfoliation and that as more layers exfoliated

the stronger the impact of toxicity. This has been associated with the increase of surface

area and the number of active edge sites (Chang, 2014).

5. Strategic Insights for the UK

To make sense of the trends in the innovation landscape of non-carbon 2D materials and

how these should shape the UK’s industrial approach to this family of 2D materials, KTN

consulted with industry and academia to look at opportunities and challenges. Table 10

sums up a wide range of potential applications with significant export opportunities for the

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UK. KTN asked the industry experts for their views on the timings of these opportunities.

The outcome is shown as Figure 2, with sensors and structural composites seen as the

applications with short to medium term opportunities for commercialisation.

Table 10: Applications for non-carbon 2D materials identified by the UK industrial and academic

community during stakeholder and strategy workshops and one-to-one interviews.

Energy generation, harvesting and storage - High power density batteries. Nanosheets as battery electrodes. - Fuel Cells - Energy storage - Hydrogen storage

Health - Surface functionalization - Bio sensors - Smart wearables

Electronics and semiconductors - Flexible electronics - Display backplanes - Novel and integrated optoelectronics (e.g. lasers, switches, transistors) - Tunnelling devices. Insulating or semiconductor 2D material combined with graphene

to create a tunnel junction - Optoelectronic devices - Thermal cooling fluids for electronics (oil/water based) - Semiconductor heterostructure devices for power saving - Microelectronics

Quantum technologies - Single photon sources

Composites - Nanocomposites (in thermoset and thermoplastic polymers) for electrical insulating

applications like power cables and distribution components. - Structural composites - Multifunctional composites

Ambient barriers - Packaging. Barrier material for food/electronics and no additives for electronics. - Water vapour and gas barriers. - Anti-corrosion barriers.

Lubrication for other materials

Environmental - Membranes for water treatment

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Figure 2: Commercialisation timescale for non-carbon 2D materials applications.

Challenges

High quality and large-scale synthesis are key barriers to the commercialisation and

application of non-carbon 2D materials. In the case of hBN this is due to the lack of large

scale demand from industry. A number of other technical challenges were identified in the

KTN study. These are summarised in Table 11.

Table 11: Technical challenges of non-carbon 2D materials. Input from KTN stakeholder and

strategy workshops (2016/17).

Technical challenges

Cost and time effective production. Sticky tape is time-consuming to scale up

● Scale up of heterostructures

● Lack of reliable measurements and data

● Lack of characterisation methods

● Lack of in-line characterization tools for quality control

● Lack of standards

● Reproducibility of 2D materials

● Lack of large scale synthesis and high-quality materials (lack of large scale industry

demand in the case of hBN)

● Environmental stability of some non-carbon 2D materials

● Long development path. Most are more complex than graphene

● Lack of commercially-viable, transfer/contamination free, catalyst-free production

method

● Post production handling of materials not clear

● Environmental and regulations. Toxicity, regulatory, end of life issues must be

addressed.

● Achieving good dispersion using industry relevant mixing equipment but without

damaging the platelets; Materials dispersion and stability.

● Clear demonstration of improvement in properties

Other challenges, of non-technical nature, were also identified as likely barriers to industry

take up of non-carbon 2D materials. These include the need to develop and equip supply

chains, reduction in the costs of materials and access to both public and private equity to de-

risk non-carbon 2D materials. Table 12 provides a summary of the non-technical challenges

Short term (2 yrs.)

Medium term (5 yrs.)

Long term (10 yrs.)

Commodity composites Wearables Barriers Coatings hBN Manufacturing for R&D

Sensors Structural composites Electronic packaging Membrane filters (hBN composites) Photodetectors (graphene+hBN) hBN composites for insulation

Energy generation Electronics Functional composites Quantum technologies

19

discussed in the KTN workshops.

Table 12: Non-technical challenges of non-carbon 2D materials. Input from KTN stakeholder

and strategy workshops.

Barriers to commercialisation

● Lack of relevant skills ● Lack of funding for translational journey ● Poor engagement with potential end users and customers ● Misaligned supply chain landscape – need to bring supply and value chain together ● Funding too focused on applications, need to improve manufacturing techniques ● Lack of technology roadmap for mass production and application ● Nott clear what the industrial drivers are ● High cost of raw materials and low yield ● Early stages of development for most of the materials ● Need consistent reliable sources of supply. Reliable, pure, reproducible materials

source. ● Academia and industry progress at different speeds. ● Raw materials still expensive for large scale testing ● Lack of access to finance to complete concept and R&D tasks to generate, for

example demonstration materials and hence prove applications ● Investors are sceptical that graphene and 2D materials will ever achieve their highly

speculated potential

UK Strengths

The UK has credible strengths to help overcome these key challenges. According to the

industry experts consulted, the UK can leverage learning from graphene and benefit from the

common process technologies graphene has with non-carbon 2D materials. There are UK

companies active in the synthesis and production of graphene, hBN, graphene

heterostructures and TMDCs such as MoS2. UK’s approach to open innovation and

knowledge sharing is also seen as a key strength by industry and experts are willing to

collaborate to accelerate the commercialisation of non-carbon 2D materials. Many other UK

strengths were identified and these are summarised in Table 13.

Table 13: UK strengths in non-carbon 2D materials. Input from the KTN strategy workshops.

UK strengths

- Growing capacity for manufacturing 2D materials - Strong academic research leadership and knowledge base. Knowledge base

of multi-disciplinary R&D. - Key OEMs and End-users located in the UK (automotive, aerospace, oil and

gas, wearables) - Characterisation and deposition capacity in the UK (measurement and

metrology) - Modelling and simulation capability available - Good academic and industry relationship - Existing graphene infrastructure (e.g. CPI, NGI, Cambridge, Henry Royce) - Track record of applications development - Niche companies in raw materials - Standard bodies with international reputation (BSI, NPL, etc) - Willingness and ability to learn from other sectors, e.g. pharma and electronics

20

6. Conclusions

The KTN study has identified a body of work being undertaken globally to develop non-

carbon 2D materials, mainly led by university research groups. Companies such as

Samsung and IBM are active in this area and so are UK SMEs such as Thomas Swan. The

discussions KTN have had with UK companies suggest that existing businesses with an

interest in developing commercial applications for graphene are the ones most likely to look

at exploiting other 2D materials. The following were seen as the priorities for the UK in our

bid to create commercial value from current research and industry activities:

Clear progress has been made with the commercial availability of hexagonal Boron Nitride,

hBN, and there is growing industry interest in transition-metal dichalcogenides (TMDCs), in

particular semiconductor TMDCs such as MoS2 which have direct gap and are attractive for

optics and optoelectronic devices.

There is also a particular excitement about the ability to custom stack thin layers of non-

carbon 2D materials and in combination with graphene to create hetero-structured devices.

These devices have a variety of different electronic and optical properties, which can be

finely tuned by careful design of the stack. Ongoing research is showing great promise for

new materials with specially designed electrical, magnetic, piezoelectric and optical

functionalities.

7. Priorities and recommendations

The following were seen as the priorities for the UK, by those engaged with the KTN at the

stakeholder workshops:

• More work needed to scale up the manufacturing and use of 2D materials

• Funding is needed to improve manufacturing techniques for 2D materials,

devices and products

• UK industry needs to be more open about their trends and drivers with regards to

2D materials and to work closely with academic researchers to develop

technology roadmaps for mass production and application of 2D materials

Following considerable discussions with industry and UK academics, the following

recommendations are made to both government and industry to drive forward the

commercialisation of non-carbon 2D materials in the UK.

1. Create an Industry Challenge around hBN and MOS2 to accelerate the

development of supply chain and end user partnerships

2. Provide 5-10 years long term funding for centres of excellence to carry out

more work needed in scale-up of non-carbon 2D material production, device

fabrication and end-user applications

3. Consider the overall UK landscape and alignment with the EU Graphene

Flagship project

21

4. Provide funding for scaled demonstrators to show and exploit the game

changing properties of non-carbon 2D materials, solely or in combination with

graphene.

Acknowledgements

KTN would like to express sincere thanks to the many individual experts and organisations

that have contributed to this review and analysis. In particular, we would like to thank the

many contributors who attended the stakeholder and strategy workshops and also those

who spoke to us during visits and completed the online questionnaire.

22

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23

Appendix 1: Examples of R&D and Innovations

Table A1: Examples of other innovations developed by the UK and non-UK organisations.

R&D work Organization Innovation

Light-emitting diodes by band-structure engineering in van der Waals heterostructures

University of Manchester Application

Molecular Beam Epitaxy of 2D Materials University of Sheffield (Presentation)

Manufacturing

2D Materials beyond Graphene for Electrical and Optical Device Applications

City University (Presentation)

Application

Ionic solutions of 2-dimensional materials UCL (Presentation Synthesis

Electronic properties of graphene-boron nitride tunnel transistors

University of Nottingham & Manchester

Application

Van der Waals epitaxy of monolayer hexagonal boron nitride on copper

Imperial College Synthesis

CVD technology for 2D materials: transition metal dichalcogenides

University of Southampton Synthesis

Standards for graphene and 2D materials. Terminology

NPL Standard

Metrology for 2D materials NPL Characterization

CVD-based 2D film technology Cambridge (Presentation) Synthesis

MoS2 for friction and wear reduction University of Leeds (Presentation)

Application

Single quantum emitters in monolayer semiconductors

University of Science and Technology of China

Synthesis

Modelling and simulation of silicene Aix-Marseille University Materials

Atomically thin p-n junctions with van der Waals heterointerfaces

Columbia University Application

The valley Hall effect in MoS2 transistors Cornell University Application

Germanene on gold substrate Instituto de Ciencia de Materiales de Madrid-ICMM-CSIC

Synthesis

Photoluminescence in Monolayer MoS2 University of California Application

Van der Waals stacked 2D layered materials for optoelectronics

Shenzhen University Application

Synthesis of Two-Dimensional Materials for Capacitive Energy Storage

University François Rabelais of Tours

Application

24

Appendix 2: Patent analysis

Google patent database was used to search for patented technologies. Advanced search of

keyword “2D materials” was conducted and 486 hits were obtained.

Non-UK Patents

Two-dimensional materials and methods for ultra-high density data storage and retrieval, Hewlett-Packard Development Co LP

Memory devices including two-dimensional material, methods of manufacturing the same, and methods of operating the same, Samsung Electronics Co Ltd

Mems, Infineon Technologies AG

Method of manufacturing a junction electronic device having a 2-dimensional material as a channel, Electronics and Telecommunications Research Institute

Local doping of two-dimensional materials, University of California

Electronics device having two-dimensional (2d) material layer and method of manufacturing the electronic device by inkjet printing, Samsung Electronics Co Ltd

3D UTB transistor using 2D material channels, Taiwan Semiconductor Manufacturing Co

Electromechanical switching device with 2d layered material surfaces, GlobalFoundries Inc

Inverter including two-dimensional material, method of manufacturing the same and logic device including inverter, Samsung Electronics Co

Growth of Crystalline Materials on Two-Dimensional Inert Materials, US Secretary of Navy